Joint Optimization of Aerodynamics and Aeroacoustics of Side View Mirrors

This thesis is carried out at China Euro Vehicle Technology (CEVT) and aims at
developing a method for performing multidisciplinary optimization for automotive
applications. Such applications could be to optimize side mirrors, a-pillars, spoilers
etc. for disciplines such as aerodynamics, aeroacoustics, contamination etc. For this
thesis the optimization is performed in terms of aerodynamics and aeroacoustics on
the side view mirrors of a passenger car. Another part of the thesis is to investigate
the possibilities to post process and analyse the results, in order to find and
understand the design parameters and how they affect the different disciplines. Two
design parameters are used in the study. One parameter is the position of the mirror
along the car and the other is the angle between the side of the car and the inside
of the mirror. The optimization procedure follows four steps. The geometry is first
morphed in the pre processing program ANSA into the design that will be simulated.
A surface mesh is saved as a geometry representation. The second step is that the
surface mesh is loaded into FLUENT meshing which creates the simulation domain
and the volume mesh. Step two is performed in two separate session simultaneously,
one for the aerodynamic and one for the aeroacoustic simulations. The next step is
that the volume mesh is read by FLUENT which simulates the flow and calculates
the optimization parameters, drag for the aerodynamic simulations and sound pressure
level for the aeroacoustic simulations. The final step is that the optimization
program HEEDS determines the new morphing parameters to send to ANSA based
on the results from the previous simulations. A bash script was written which reads
the design parameters from a separate file and runs ANSA and FLUENT in the
correct order. HEEDS changes the design parameters in this separate file and then
runs the bash script to obtain the output variables. After the output is obtained the
process starts over. It was found that the angle of the inside of the mirror should
be increased slightly to reduce drag and SPL. The optimal choice of the x-position
seemed to be outside of the investigated interval, moving the mirror as far back on
the car as possible was best in terms of drag. The effect the x-position had on the
noise on the side window was very small.

BibTeX @mastersthesis{Stridh2018,author={Stridh, Mattias},title={Joint Optimization of Aerodynamics and Aeroacoustics of Side View Mirrors},abstract={This thesis is carried out at China Euro Vehicle Technology (CEVT) and aims at
developing a method for performing multidisciplinary optimization for automotive
applications. Such applications could be to optimize side mirrors, a-pillars, spoilers
etc. for disciplines such as aerodynamics, aeroacoustics, contamination etc. For this
thesis the optimization is performed in terms of aerodynamics and aeroacoustics on
the side view mirrors of a passenger car. Another part of the thesis is to investigate
the possibilities to post process and analyse the results, in order to find and
understand the design parameters and how they affect the different disciplines. Two
design parameters are used in the study. One parameter is the position of the mirror
along the car and the other is the angle between the side of the car and the inside
of the mirror. The optimization procedure follows four steps. The geometry is first
morphed in the pre processing program ANSA into the design that will be simulated.
A surface mesh is saved as a geometry representation. The second step is that the
surface mesh is loaded into FLUENT meshing which creates the simulation domain
and the volume mesh. Step two is performed in two separate session simultaneously,
one for the aerodynamic and one for the aeroacoustic simulations. The next step is
that the volume mesh is read by FLUENT which simulates the flow and calculates
the optimization parameters, drag for the aerodynamic simulations and sound pressure
level for the aeroacoustic simulations. The final step is that the optimization
program HEEDS determines the new morphing parameters to send to ANSA based
on the results from the previous simulations. A bash script was written which reads
the design parameters from a separate file and runs ANSA and FLUENT in the
correct order. HEEDS changes the design parameters in this separate file and then
runs the bash script to obtain the output variables. After the output is obtained the
process starts over. It was found that the angle of the inside of the mirror should
be increased slightly to reduce drag and SPL. The optimal choice of the x-position
seemed to be outside of the investigated interval, moving the mirror as far back on
the car as possible was best in terms of drag. The effect the x-position had on the
noise on the side window was very small.},publisher={Institutionen för mekanik och maritima vetenskaper, Strömningslära, Chalmers tekniska högskola},place={Göteborg},year={2018},series={Examensarbete - Institutionen för mekanik och maritima vetenskaper, no: 2018:32},keywords={Aeroacoustics, Aerodynamics, CFD, DES, Drag, MDO, SPL},}

RefWorks RT GenericSR ElectronicID 255222A1 Stridh, MattiasT1 Joint Optimization of Aerodynamics and Aeroacoustics of Side View MirrorsYR 2018AB This thesis is carried out at China Euro Vehicle Technology (CEVT) and aims at
developing a method for performing multidisciplinary optimization for automotive
applications. Such applications could be to optimize side mirrors, a-pillars, spoilers
etc. for disciplines such as aerodynamics, aeroacoustics, contamination etc. For this
thesis the optimization is performed in terms of aerodynamics and aeroacoustics on
the side view mirrors of a passenger car. Another part of the thesis is to investigate
the possibilities to post process and analyse the results, in order to find and
understand the design parameters and how they affect the different disciplines. Two
design parameters are used in the study. One parameter is the position of the mirror
along the car and the other is the angle between the side of the car and the inside
of the mirror. The optimization procedure follows four steps. The geometry is first
morphed in the pre processing program ANSA into the design that will be simulated.
A surface mesh is saved as a geometry representation. The second step is that the
surface mesh is loaded into FLUENT meshing which creates the simulation domain
and the volume mesh. Step two is performed in two separate session simultaneously,
one for the aerodynamic and one for the aeroacoustic simulations. The next step is
that the volume mesh is read by FLUENT which simulates the flow and calculates
the optimization parameters, drag for the aerodynamic simulations and sound pressure
level for the aeroacoustic simulations. The final step is that the optimization
program HEEDS determines the new morphing parameters to send to ANSA based
on the results from the previous simulations. A bash script was written which reads
the design parameters from a separate file and runs ANSA and FLUENT in the
correct order. HEEDS changes the design parameters in this separate file and then
runs the bash script to obtain the output variables. After the output is obtained the
process starts over. It was found that the angle of the inside of the mirror should
be increased slightly to reduce drag and SPL. The optimal choice of the x-position
seemed to be outside of the investigated interval, moving the mirror as far back on
the car as possible was best in terms of drag. The effect the x-position had on the
noise on the side window was very small.PB Institutionen för mekanik och maritima vetenskaper, Strömningslära, Chalmers tekniska högskola,T3 Examensarbete - Institutionen för mekanik och maritima vetenskaper, no: 2018:32LA engLK http://publications.lib.chalmers.se/records/fulltext/255222/255222.pdfOL 30